Weird color on texture painting with brush
I think you tapped it. I've been trying to recreate the pink and RED is the direction any change in Saturation goes. As I approach .03, the pink begins to stand out if I see all your other settings correctly.

I'm not sure about creating palettes and how much protection that affords from changing colors. In my opinion you took the right steps by restarting and opening a saved version. I almost want to point some blame toward the alpha but that seems pretty locked in.

Triple check that color swatch and don't get fancy with any button shortcuts while painting in case one of them toggled some setting we're not thinking of. Checking Accumulate and Add for the Blend mode might also restore white where you need it if things are still rosy.